Computer technology continues to advance at a rapid pace, with significant developments being made in both software and in the underlying hardware upon which the software executes. One significant advance in computer technology is the development of multi-processor computers, where multiple computer processors are interfaced with one another to permit multiple operations to be performed concurrently, thus improving the overall performance of such computers. Also, a number of multi-processor computer designs rely on logical partitioning to allocate computer resources to further enhance the performance of multiple concurrent tasks.
With logical partitioning, a single physical computer is permitted to operate essentially like multiple and independent virtual computers (referred to as logical partitions), with the various resources in the physical computer (e.g., processors, memory, and input/output devices) allocated among the various logical partitions. Each logical partition may execute a separate operating system, and from the perspective of users and of the software applications executing on the logical partition, each separate operating system appears as a fully independent computer.
A hypervisor or partition manager, shared among the logical partitions, manages the logical partitions and allocates resources to the different logical partitions. If the partition manager encounters an error that prevents the partition manager from continuing to operate, the partition manager may need to be restarted via a technique known as a re-IPL (re-Initial Program Load). But, an ordinary IPL destroys the contents of volatile memory, which could contain information regarding the configuration of the partitions, which would be helpful on the re-IPL. The partition manager typically does not have an associated disk drive or other non-volatile memory in which to store its configuration information following an error because the partition manager typically allocates all disk drives on a per-disk drive basis to the logical partitions, which greatly simplifies the management of the logical partitions. Adding an additional disk drive solely for use by the partition manager would increase the cost of the system and decrease its competitiveness in the marketplace.
Thus, without a cost-effective way to preserve memory contents, the acceptance of computers with multiple partitions is hampered. Although the aforementioned problems of memory preservation have been described in the context of a logically-partitioned computer, they may also apply to other electronic devices.